SteveJ

You nailed it. See, it's not that hard to figure things out.

Nicely done.

You are definitely missing a wire. My $0.02: The wire for the running lights came off of the contact on the switch. The PO starting hacking wires because he didn't know how to fix it properly.

When you turn on the hazard lights, the switch opens up the circuit that goes to the brake switch, and it opens up the circuit that goes to the turn signal flasher relay. If the hazard switch was affecting the brake lights, it would affect BOTH brake lights. https://fiddlingwithzcars.wordpress.com/2013/01/13/early-hazard-switch/

The FSM has a lot of good information in the BE section once you learn how to use it. For the wiring diagram, it's best to start at one point, such as the switch) and carefully follow the line to the other point, like the light bulb or fuse box. In reality, the wiring is broken down by the engine harness, dash harness, and body harness. The FSM shows the connections between the harnesses and what wire color should be at what point in the connector. You may have to pull the dash and examine the dash harness closely to get rid of the mistakes of the previous owner.

We were all amateurs at one time. Consider this the motivation to improve your skills.

I forgot that the 73 also had the 9 pin connector. It's time for you to develop a lot of proficiency in reading wiring diagrams and fixing wiring. Vintage Connections (http://www.vintageconnections.com) has most of the connectors you will need and good extracting tools to remove connectors from the shells.

I admit that I ran a drill through some of the holes to make them compatible with the Ford fender rivets. The change in size is very small.

It's the turn signal switch. https://fiddlingwithzcars.wordpress.com/2013/01/20/hazard-switch-brake-light-turn-signal-circuit-analysis/ https://fiddlingwithzcars.wordpress.com/2012/12/04/turn-signal-repair/ You can contact @Zs-ondabrain about cleaning/repairing it. His turnaround time is a LOT faster than mine, and he's on the same side of the country as you are.

It's a 74-76 switch. The green/white wire is for the running lights. All I can say is, "Ugh! Wire nuts!" @krZing, you have a mess on your hands.

Better option: http://www.classiczcars.com/forums/topic/40103-fasteners-for-trim-panels/

If your other gauges work, you know you have voltage at the gauge. On page BE-2 of the FSM, you will find the connections between the engine harness and dash harness. Here is the tricky part. The wiring diagram on BE-5 says there are two yellow/white wires going to the engine bay. One is for the temperature gauge sender, the other is for the oil pressure sender. However, BE-2 only shows one. I believe that the yellow/white wire shown on the six connector shell is for the temperature gauge sender. You could try grounding it on the dash harness side to see if the gauge moves. Otherwise, you might need to pull the gauge and bench test it.

Try the Z Car Garage in San Jose. http://www.zcargarage.com

It sounds like your voltage is getting too low. Is it an internally or externally regulated alternator? If it is externally regulated (stock), test it per the BE section of the 260Z FSM. If car has been converted to use an internally regulated alternator, test per the BE section of the 1978 280Z FSM.

Thank you, @kats, for taking the time to post these diagrams. They are of excellent quality.

Okay, I'm tracking with you now. There should be differences between the US and JDM wiring, and I do not know if any of the differences are in the turn signal or headlight circuits. @Patconcould be pointing you in the right direction on grounding issues. When you use the turn signals and the headlights come on, are they normal brightness or dim? Can they change between high and low beam? @kats Do you have a source for the Japanese wiring diagram that you could post?

The contacts should be closed.

The brake light circuit is interrupted at the turn signal. It is after the hazard light switch. Since you said your right turn signal works, it is most likely the turn signal switch. https://fiddlingwithzcars.wordpress.com/2012/12/04/turn-signal-repair/

The turn signals will not work when you are using the hazard lights. The switch for the hazard lights cuts off the power to the turn signals. What do you mean by "headlights come on solid"? Also is this a genuine RHD JDM Z?

I had to pull the trigger, too. Thank you, @Zed Head for the info!

You will have to track the circuit all the way through. Something got rewired somewhere. If you have 12VDC on each leg going out of the turn signal switch, continue tracing it down the line, such as at the C3 and C4 connectors between the dash harness and other harnesses. Also, you said you are "pretty sure" the flasher relays are good. Why do you think they are good? The hazard circuit especially seems like the flasher is not good or there is not enough load in the circuit for the bimetal strip (if it's an old relay) to work. There could to be things going on in the wiring that you do not see or do not recognize as being different/wrong. Please go back through this thread and look for questions I asked that you did not answer. There are pieces to this puzzle that are missing.

So, is the turn signal switch a 76 or 77 switch? I see that the hazard switch is for a 77. Do you see any splices in the harness where the 77 connector(s) was(were) put in? Please note that the wire colors in the wiring diagrams applies ONLY to the wire harness. Sometimes components have wire colors that differ from the wire harness. I have disassembled and reassembled both types of switches. https://fiddlingwithzcars.wordpress.com/2013/07/11/late-280z-turn-signal-switch/ https://fiddlingwithzcars.wordpress.com/2012/12/04/turn-signal-repair/ You can see they are designed completely differently. There are only 3 wires going to the 280Z turn signal switch: positive 12 VDC, left and right. On the 240Z there are 6 wires.

Now you have me confused. What 77 switches did you put in your 76? How did you get the incompatible connectors to connect?

I believe the connectors are different between the 76 and 77 turn signal switches. Please post photos of the connector on the turn signal switch and the connector in the body harness. Try to get the wire colors, too. Also, are you using incandescent or LED bulbs in the car?

The routing on the 73 & 74 is on the right side of the transmission tunnel and crosses over the valve cover. If you get stuck finding it, let me know, and I can supply a photo.